@color:red;
@width:100%;
@height:100%;
@navbarHeight:80px;

//html,body{
//  height: @height;
//}
html,body,p,ul,li{
  padding: 0;
  margin: 0;
}
header{
  width: @width;
  height:@navbarHeight;
  background-color: @color;

}

#content{
  width: 800px;
  height: 400px;
  border: 1px solid gray;
  margin: 100px auto 0;
  position: relative;
  overflow: hidden;

}
#content div{
  transition: 0.5s;
}